Page 73 - CITS - Electrician - Trade Practical

ELECTRICIAN - CITS

EXERCISE 29 : To measure the voltage & current in Star

and Delta connection

Objectives

At the end of this exercise you shall be able to
• draw the circuit diagram of Star & Delta connection
• make the connection of Star & Delta circuit.
• measure the line voltage & current and phase voltage & current in Star - Delta.
• apply the Star-Delta applications in AC machines.

Requirements

Tools/Equipments Materials

• Combination Plier (150 mm, • PVC copper wire
insulated) - 1 No. 1.5 sq mm - as reqd.
• Screw driver 150mm, insulated • Incandescent bulb 100 W, 230 V - 6 Nos.
stem - 1 No. • Lamp holder 6 A, 250 V - 6 Nos.
• Neon tester 75mm, 500V - 1 No. • TPST switch 415 V, 32A - 1 No.
• Electrician knife • Banana sockets 4mm, 10 A - 10 Nos.
• Voltmeter, MI 500 V - 2 Nos. • Wooden board TW, 2’ X 2’ - 1 No.
• Ammeter, MI 10 A - 2 Nos.
• Induction motor 3 ph. 415 V, 2HP - 1 No.

Procedure

TASK 1: Connection of STAR circuit and testing

1 Draw the circuit diagram of STAR connection.
2 Fix the lamp holders & banana sockets in STAR fashion on wooden board.
3 Make the connection of lamp holders & banana sockets.
4 Fix the bulbs in lamp holders and connect the voltmeter & ammeter as per STAR connection circuit.
5 Check the circuit and connect 3 ph. supply through TPST switch

6 Switch ON TPST switch and measure the line & phase voltage and line & phase current.
7 Switch OFF the supply and disconnect the circuit.

TASK 2: Connection of DELTA circuit and testing
1 Draw the circuit diagram of DELTA connection.
2 Fix the lamp holders & banana sockets in DELTA fashion on wooden board.

3 Make the connection of lamp holders & banana sockets.
4 Fix the bulbs in lamp holders and connect the voltmeter & ammeter as per DELTA connection circuit.
5 Check the circuit and connect 3 ph. supply through TPST switch.
6 Switch ON TPST switch and measure the line & phase voltage and line & phase current.
7 Switch OFF the supply and disconnect the circuit.

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